Since these parts slide against their associated parts under high pressures, it is of vital importance that they are not only wear-resistant in themselves, but they do not also wear away their associated parts. The conventional parts of this type are formed of steel or cast iron and are improved in respect of wear resistance by chilling, spraying of autogenous alloys or hard-chromium plating. However, some problems arise in connection with cost and performance. Thus there is still an increasing demand for the development of more satisfactory materials.
It is known in the art that, in some cases, a so-called dispersion-hardened type of sintered alloy, viz., a sintered alloy having a metal matrix throughout in which is dispersed a phase harder than the said matrix, is well suited for such application. However, this type of alloy has its properties affected noticeably by the nature and density ratio (say, porosity) of the matrix as well as the component and distribution of the hard phase. This leads to difficulties encountered in the steady production of alloys having the desired properties, too.